System and method of use for self-contained vehicular navigation system

1. A system comprising: at least one wheel-rotation sensor operative to detect and convey wheel-rotation data signals; a magnetic sensor operative to detect and convey compass direction data signals for a vehicle's direction of travel; a satellite positioning receiver subsystem operative to receive a plurality of satellite positioning signals then determine and convey the location coordinates of its position; a graphical user interface operative to convey user inputs to an I/O subsystem; said graphical user interface operative to receive and display inputs from said I/O subsystem; a navigation subsystem comprising: a processing unit; maps data memory storage; and program memory; at one least program, executed by said processing unit, operative to direct capturing and storing of a succession of said wheel-rotation data; said at least one program operative to direct capturing and storing of a succession of said location coordinates of said satellite positioning receiver subsystem; said succession of wheel-rotation data and said succession of said location coordinates are captured concurrently; said at least one program operative to direct computing of a first speed based on said succession of said wheel-rotation data; said at least one program operative to direct computing of a second speed based on said succession of said location coordinates; said at least one program operative to compare said first speed to said second speed; said at least one program operative to compute a calibration factor by which said first speed when multiplied by said calibration factor is equal to said second speed; said at least one program operative to multiply later captures of said wheel-rotation data by said first calibration factor and to use result to compute vehicle speed; said at least one program, executed by said processing unit, operative to direct capturing and storing of a succession of said compass direction data; said at least one program operative to direct capturing and storing of a succession of said location coordinates of said satellite positioning receiver subsystem; said succession of said compass direction data and said succession of said location coordinates are captured concurrently; said at least one program operative to direct computing of a first compass direction based on said succession of said compass direction data; said at least one program operative to direct computing of a second compass direction on said succession of said location coordinates; said at least one program operative to compare said first compass direction to said second compass direction; said at least one program operative to compute a signed calibration offset by which said first compass direction when summed with said calibration offset is equal to said second compass direction; and said at least one program operative to add said signed calibration offset to later captures of said compass direction data conveyed by said magnetic sensor subsystem.

2. A method relying on programmatic calibration of sensor data with corresponding satellite position data comprising: establishing an initial vehicle location; inputting a destination location reference; plotting on a display a route linking said initial vehicle location and said destination location; capturing, with a processing unit, vehicle speed based on wheel-rotation data; capturing, with a processing unit, vehicle direction heading based on magnetic sensor data; tracking vehicle position based on said vehicle speed, said vehicle direction and elapsed time; plotting on said display said vehicle position using said route as a backdrop; establishing an initial vehicle location using received satellite positioning data coordinates; calibrating, with a processing unit, a wheel-rotation sensor against speed derived from said received satellite positioning data coordinates; calibrating, with a processing unit, a magnetic sensor and correcting said magnetic sensor data against direction derived from said satellite positioning data coordinates, storing vehicle location coordinates just prior to power down of vehicle; and using stored said vehicle location coordinates as said initial vehicle location just after powering up of vehicle; and establishing, in the absence of said satellite positioning data, said initial vehicle position based on user input in view of maps data.